Open roof construction for a vehicle

ABSTRACT

An open roof construction for a vehicle having a roof opening that can be closed by a movable closure element. A sliding sunscreen is positioned under the closure element, wherein the sunscreen at least partially is a material that exhibits variable light transmission. The light transmission can be varied automatically or manually.

BACKGROUND OF THE INVENTION

[0001] The invention relates to an open roof construction for a vehicle,having a roof opening which can be closed by a movable closure element,wherein the element is used for varying the light transmission throughthe roof opening.

[0002] In order to enhance the degree of comfort in a vehicle fittedwith an open roof construction having a roof opening approaches aresought for varying the amount of incident light through the roofopening. Dutch patent application no. 9102116, from which the presentinvention departs, discloses an open roof construction wherein theclosure element consists of a sliding panel, which is provided with acoating that exhibits variable light transmission. The variable lighttransmission proves to be advantageous when the panel closes the roofopening entirely or for the greater part. However, when the panel ismoved to a position in which it opens the roof opening, the coatingexhibiting variable light transmission loses its function.

[0003] Another approach used in prior art open roof constructions is asunscreen present under the closure element. In this case, lighttransmission through the roof opening can be varied by changing theposition of the sunscreen to a greater or lesser degree so as to coverthe roof opening to a greater or lesser degree. In fact, the designeropts for a principle whereby the extent of the shade provided by thesunscreen is varied. In principle, there is no regulation of lightintensity.

SUMMARY OF THE INVENTION

[0004] In accordance with one aspect of the present invention, the openroof construction includes a sliding sunscreen positioned under theclosure element, wherein the sunscreen at least partially has a materialthat exhibits variable light transmission. The roof opening can becovered by the sunscreen to a degree that can be freely selected.Consequently, it is possible in the selected position of the sunscreento vary light transmission through a roof opening.

[0005] Within the scope of the invention the sunscreen may consistsubstantially entirely of a material that exhibits variable lighttransmission. The sunscreen may also have a central portion thatexhibits variable light transmission and a frame that surrounds thecentral portion, wherein the frame consists of a material that does notexhibit variable light transmission.

[0006] In the latter case an advantageous embodiment may be one whereinthe central portion can be detached from the surrounding frame. In thisway it is possible to build a central portion into any conventionalsunscreen prior to, during and after the fitting of the open roofconstruction in a vehicle.

[0007] The open roof construction according to the invention provides anumber of advantages. The construction according to the presentinvention can be used with practically any conventional open roofconstruction. Since the movable closure element no longer has a coatingor a portion that exhibits variable light transmission, as is the casewith the prior art, the design restrictions with regard to the closureelement are less stringent. Furthermore, possible damage to thelight-transmitting material can be repaired more easily and at lowerexpense, since it is only necessary in the worst case to replace thesunscreen. Whereas, in the prior art, it would be necessary in the worstcase to replace the entire closure element.

[0008] In spite of the fact that the sunscreen now consists, at leastpartially so, of a material that exhibits variable light transmission,the sunscreen can continue to perform other functions, such as acousticand thermal insulation. This enables the sunscreen to provide the samedegree of luxury as any other conventional sunscreen.

[0009] In another embodiment of the open roof construction according tothe present invention, light transmission is varied automatically. Thiscan for example be achieved when light transmission is varied on thebasis of measured quantities inside the vehicle, such as light intensityor temperature, for example. For instance, if the temperature inside thevehicle rises or threatens to rise too high, the degree of lighttransmission can be reduced automatically, thus reducing the heatinginfluence of the incident light.

[0010] It is also possible, of course, to vary the light transmissionmanually. In that case the driver or a passenger of the vehicle canselect a degree of light transmission to his or her liking.

[0011] An electrochromatic material may be selected as a suitablematerial exhibiting variable light transmission. Components consistingof such electrochromatic material are known and can be used inaccordance with widely varying specifications.

[0012] An inexpensive variant of the open roof construction according tothe invention provides an embodiment wherein the material that exhibitsvariable light transmission consists of polarisation filters arranged inside-by-side relationship, which can be pivoted or otherwise moved withrespect to each other. As is known, the amount of light penetratingthrough the polarisation filters can be regulated between a maximumvalue and a minimum value by pivoting the two filters relative to eachother.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The invention will be explained in more detail hereafter withreference to the drawings, which shows a number of embodiments of theopen roof construction according to the invention.

[0014]FIG. 1 is a schematic, longitudinal sectional view of a part of anembodiment of the open roof construction according to the presentinvention.

[0015]FIG. 2 is a bottom plan view of an embodiment of a sunscreen asused in the open roof construction according to the present invention.

[0016]FIG. 3 is a bottom plan view of another embodiment of a sunscreen.

[0017]FIG. 4 is a bottom plan view of yet another embodiment of asunscreen.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

[0018]FIG. 1 is a schematic longitudinal sectional view of a part of anopen roof construction according to the invention. The figure shows apart of the fixed roof construction 1 of the vehicle. A roof opening 2has been formed in roof construction 1, wherein roof opening 2 can beclosed by a movable closure element 3. In the embodiment illustrated,movable elements 3 is a sliding panel. The panel 3 can be moved(substantially slid), in a known manner to a position 3′, illustrated indotted lines, where the roof opening 2 is released to a greater orlesser extent.

[0019] Present under the fixed roof construction 1 and under panel 3 isa sliding sunscreen 4. As is known, sunscreen 4 is capable of slidingmovement in a direction substantially parallel to the fixed roofconstruction 1 and to panel 3, between a retracted position, in whichsunscreen 4 releases root opening 2 to a large extent, and an operativeposition, in which sunscreen 4 essentially overlaps the roof opening 2.Sunscreen 4 can also take up any position therebetween, of course,depending on the user's wishes. Sunscreen 4 can also be fitted with ahandle 5 in the illustrated embodiment to provide a user with a grip onsunscreen 4.

[0020] In accordance with the invention, sunscreen 4 includes, at leastpartially, a material that exhibits variable light transmission. In theexemplary embodiment illustrated in FIG. 1, sunscreen 4 may for exampleconsist of an electrochromatic material, whose light transmission can beregulated under the influence of an electric current. To this end, againin the embodiment that is shown in FIG. 1, a sensor 6 (a temperaturegauge, for example) is present in the interior of the vehicle, whereinthe sensor 6 controls the sunscreen 4. In particular, sensor 6 isadapted to provide a signal to control unit 7. If control unit 7determines that the temperature measured by sensor 6 has exceeded apredetermined value, a signal is delivered to the sunscreen 4 (inparticular the electrochromatic material thereof) to decrease the lighttransmission thereof. As a result, the incidence of sunlight in thevehicle is reduced, making it possible to regulate the temperatureinside the vehicle. Within this framework it is noted that the controlunits can also drive other elements for regulating the temperature, suchas a ventilation system.

[0021] Another, non-limitative, example of a sensor 6 is called aphotometer, which measures the intensity or extent of the light insidethe vehicle. The use of sensor 6 and control unit 7 makes it possible toeffect automatic variation of the light transmission of sunscreen 4. Itis also possible, of course, for the light transmission to be manuallyvaried by the driver or by a passenger of the vehicle with a useroperated switch 15. When a sunscreen 4 consisting of an electrochromaticmaterial is used, a desired value can be adjusted for the current or thevoltage that is applied to the sunscreen 4 by an adjusting element, forexample a potentiometer.

[0022] FIGS. 2-4 show three possible variants of embodiments of thesunscreen. It is noted that other embodiments fall within the scope ofthe invention.

[0023]FIG. 2 shows an embodiment of a sunscreen 4′ with a major surfaceextent that consists in its entirety of a material that exhibitsvariable light transmission. This may be an electrochromatic or aphotochromatic material, for example.

[0024] In the embodiment shown in FIG. 3, sunscreen 4″ has a centralportion 9, which is made of a material that exhibits variable lighttransmission, and a frame 10 surrounding central portion 9, which ismade of a material that does not exhibit variable light transmission.

[0025] In the embodiment illustrated in FIG. 4, two polarisation filtersthat can be pivoted with respect to each other are arranged inside-by-side relationship in the sunscreen 41′″. The filters are onlyschematically represented by hatched lines 11 and dotted hatched lines12. Since each polarisation filter has a specific polarisationdirection, the overall light transmission through the polarisationfilters 11 and 12 can be varied between a value of substantially zeroand a maximum value by pivoting or otherwise moving the two filters 11and 12 with respect to each other. In the illustrated embodiment, amanually operated rotary knob 13 is used for pivoting the polarisationfilters 11 and 12 with respect to each other. Similar to that which hasbeen noted with regard to the embodiment of FIG. 1, it is also possibleto automate the pivoting or moving of the polarisation filters using anelectric motor, for example, driven by control unit 7 that receives asignal from sensor 6.

[0026] Those skilled in the art will recognize that the variation of thelight transmission of the light-transmitting material 8 and 9 of FIGS. 2and 3, respectively, can take place automatically as well as manually.In addition, combinations of automatic and manual variation arepossible.

[0027] In the embodiments illustrated in FIGS. 3 and 4, it may bepossible to detach the portion consisting of light-transmitting material(material 9 and polarisation filters 11 and 12, respectively) from thesurrounding frame 10 and 14, respectively, of the sunscreen. In thismanner, the portion consisting of a material exhibiting variable lighttransmission can be replaced quickly and easily if the portion should bedamaged.

[0028] The open roof construction according to the invention makes itpossible to adapt existing open roof constructions afterwards in a quickand simple manner in accordance with the specifications of the presentinvention. Referring by way of example to the embodiment of FIG. 3, itis only necessary to form a central opening in a conventional sunscreenthat has already been mounted, in which opening the material exhibitingvariable light transmission is fitted. If said material is anelectrochromatic material, the only thing that needs to be done in thatcase is to connect a power supply line to the sunscreen. In that case acontrol unit (automatic or manual) can be mounted at a suitable locationin the vehicle, for example in the roof upholstery.

[0029] The invention is not restricted to the above-describedembodiments, which can be varied in several ways without departing fromthe scope of the invention as defined in the claims.

What is claimed is:
 1. An open roof construction for a vehiclecomprising: a roof opening that can be closed by a movable closureelement; and a sliding sunscreen positioned under the closure element,wherein the sunscreen at least partially comprises a material thatexhibits variable light transmission.
 2. The open roof constructionaccording to claim 1 , wherein a major surface extent of the sunscreencomprises substantially entirely of a material that exhibits variablelight transmission.
 3. The open roof construction according to claim 1 ,wherein the sunscreen comprises a central portion that exhibits variablelight transmission and a frame that surrounds the central portion,wherein the frame comprises a material that does not exhibit variablelight transmission.
 4. The open roof construction according to claim 3 ,wherein the central portion is detachable from the surrounding portion.5. The open roof construction according to claim 1 , wherein the lighttransmission of the material can be varied automatically.
 6. The openroof construction according to claim 5 , wherein the light transmissionof the material is varied as a function of the value of measuredquantities inside the vehicle.
 7. The open roof construction accordingto claim 6 , wherein the light transmission of the material is varied asa function of light intensity.
 8. The open roof construction accordingto claim 6 , wherein the light transmission of the material is varied asa function of temperature.
 9. The open roof construction according toclaim 1 , wherein the light transmission can be varied manually.
 10. Theopen roof construction according to claim 1 , wherein the materialexhibiting variable light transmission is an electrochromatic material.11. The open roof construction according to claim 1 , wherein thematerial that exhibits variable light transmission comprisespolarization filters arranged in side-by-side relationship that can bemoved with respect to each other.
 12. The open roof construction ofclaim 1 and further comprising a control unit coupled to the sunscreento control light transmission of the sunscreen.
 13. The open roofconstruction of claim 12 and further comprising a sensor coupled to thecontrol unit, the sensor providing a signal indicative of light in thevehicle.
 14. The open roof construction of claim 12 and furthercomprising a user operated device to provide a signal indicative of auser setting for light transmission through the sunscreen.
 15. Asunscreen adapted for sliding movement in an open roof construction of avehicle, the sunscreen at least partially comprising a material thatexhibits variable light transmission.
 16. The sunscreen of claim 15 andfurther comprising a control unit coupled to the sunscreen to controllight transmission of the sunscreen.
 17. The sunscreen of claim 16 andfurther comprising a sensor coupled to the control unit, the sensorproviding a signal indicative of light in the vehicle.
 18. The sunscreenof claim 17 and further comprising a user operated device to provide asignal indicative of a user setting for light transmission through thesunscreen.
 19. The sunscreen according to claim 15 , wherein a majorsurface of the sunscreen comprises substantially entirely of a materialthat exhibits variable light transmission.
 20. The sunscreen accordingto claim 15 , wherein the sunscreen comprises a central portion thatexhibits variable light transmission and a frame that surrounds thecentral portion, wherein the frame comprises a material that does notexhibit variable light transmission.
 21. The sunscreen according toclaim 20 , wherein the central portion is detachable from thesurrounding portion.
 22. An open roof construction for a vehicle,comprising: a roof opening that can be closed by a movable closureelement; and sunscreen means for varying light transmission into thevehicle.